The invention relates to an active wheel supporting system for vehicles having a scanning device which detects surface unevenness in a roadway, and active wheel support assemblies which can be controlled by the scanning device to compensate for surface unevenness detected while the vehicle is travelling.
German Patent Document DE-B 1,269,902 discloses a system of this type, for example, in which the roadway is scanned by means of a measuring beam. Deviation of the actual roadway compared to an assumed virtual roadway is determined by the measuring beam, and converted in direction and size to an adjustment of the wheel support assemblies, so that wheel movements are no longer simply a reaction to unevenness in the roadway, but rather a centrally precontrolled, intended avoidance or adjustment movement.
A similar system is the subject matter of German Patent Document DE-A 3,002,765 in which the tires can be inflated to be significantly harder without reducing comfort. Accordingly, the rolling resistance of the wheels can be reduced considerably.
Another wheel support system is disclosed in German Patent Document DE-05 40:37223, in which active support assemblies are arranged, on the one hand, between the wheels (or the axles) and the vehicle body and, on the other hand, between the wheels (or the axles) and absorption masses. It is this possible to damp both wheel movements and body movements independently of one another. The absorption masses, which can be adjusted rapidly relative to the wheels serve to reduce considerably dynamic wheel load fluctuations, and the impairment of driving safety and comfort associated therewith.
Practical tests have shown, however, that these systems do not yet operate satisfactorily.
It is therefore an object of the invention to provide a wheel support system which is comparatively simple to control, and has considerably improved operating characteristics.
This object is achieved by the wheel supporting system according to the invention, in which each wheel has a counter-mass coupled to the wheel support assembly. The counter-mass moves relative to the vehicle body in a direction opposite to that of the wheel, and compensates reaction forces associated with active wheel movements which forces act on the body.
The invention is based on the general concept of adjusting the wheels of a vehicle to previously scanned surface unevenness and, during the adjustment movements of the wheels, compensating the inevitable reaction forces between the wheels and the vehicle body by means of counter-masses guided in the opposite direction to the wheels. The vehicle body is thus kept free, to the greatest extent, from external forces caused by unevenness in the road.
In support assemblies which react sufficiently rapidly, the wheels can be adjusted virtually exactly to the surface unevenness without-a simultaneous acceleration of the vehicle body due to the readjustment movements of the wheels.
According to a preferred embodiment of the invention, the counter-mass is smaller than the mass of the wheel (and the wheel guiding elements which move with it), and the drive coupling operates with a path transmission which compensates the difference in mass, such that the reaction forces exerted on the body by the wheel (and the parts connected thereto), on the one hand, and by the counter-mass, on the other hand, are mutually compensated.
If appropriate, the magnitude of the counter-mass and/or the size of the path transmission can be variable in order to adapt to different wheel masses.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.